How Dirty Rain Water Really Is
Gene Kelly was singin' in the rain. Lil Wayne made it rain. B.J. Thomas told us raindrops kept fallin' on his head while Paul Newman and Katherine Ross dinked around on a bicycle in Butch Cassidy and the Sundance Kid. Then there's that questionably romantic scene in The Notebook with a kiss for the ages between Ryan Gosling and Rachel McAdams. Lots of water falling from the sky.
Other things can fall from the sky, certainly. But we're going to stick with water. Rain. Sometimes more than we need, sometimes not nearly enough. And just because your lawn could use a good soak doesn't mean the rest of the neighborhood wants to cancel its barbecues.
But what you really want to know is whether rain water is actually safe to drink as is. Walk through the rain, open your mouth, hydrate, repeat.
Slow down there, bucko. You might want to think again about that umbrella.
It's all fun and games until someone starts vomiting
First, bear in mind that what looks like an innocent drop of moisture is actually centered around a particle of something that isn't moisture. Dust, dirt, soot, clay, whatever. Water isn't fussy. So maybe we have to be.
The Centers for Disease Control and Prevention (CDC) warns us that rain water "is not as pure as you might think" since it can contain "bacteria, parasites, viruses, and chemicals that could make you sick, and has been linked to disease outbreaks." Yum.
Some people like to collect rain water for their own use — watering vegetation seems to be safe enough, but the CDC also cautions that some places consider rain water the property of the state and ban its collection. Also, that collected rain water should only be used to water vegetation you don't plan to eat. If you pick the dandelions out of your salad we will not be offended. Promise.
Even if you are collecting rainwater and decide to toss in a dollop or two of chlorine or iodine to purify it, the CDC warns that some parasites are "very chlorine tolerant," which is perhaps a form of tolerance we can agree is not as helpful as it might be.
None of which stopped Tom Hanks in Cast Away. Didn't seem to bother Wilson, either.